VulnerabilityModified

CVE-2021-33912

CRITICAL 9.8EPSS 9.64%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (9.64%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

libspf2 before 1.2.11 has a four-byte heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of incorrect sprintf usage in SPF_record_expand_data in spf_expand.c. The vulnerable code may be part of the supply chain of a site's e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.

CVSS 3.1: 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 9.64% probability · 95th percentile
CISA KEV: Not listed
Weakness: CWE-787
Affected: libspf2 project/libspf2 · debian/debian linux
Source: cve@mitre.org

References

https://github.com/shevek/libspf2/tree/8131fe140704eaae695e76b5cd09e39bd1dd220bThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/01/msg00015.htmlMailing List, Third Party Advisory
https://nathanielbennett.com/blog/libspf2-cve-jan-2022-disclosureExploit, Third Party Advisory
https://security.gentoo.org/glsa/202401-22
https://github.com/shevek/libspf2/tree/8131fe140704eaae695e76b5cd09e39bd1dd220bThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/01/msg00015.htmlMailing List, Third Party Advisory
https://nathanielbennett.com/blog/libspf2-cve-jan-2022-disclosureExploit, Third Party Advisory
https://security.gentoo.org/glsa/202401-22

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.